Horse-riding is apparently more dangerous than boxing. So is mountain climbing. But neither involve one person repeatedly hitting another in search of the killer punch. Boxing is in essence a blood sport. The knockout power of Frantic Assembly's co-production with the National Theatre of Scotland is that it offers a glimpse into another world. It makes you understand the thrill and the sweat, the pain and the power, the gnawing hunger and what the phrase "seeing stars" really means. This is not a pretty 100 minutes, but it taps into the natural affinities of boxing and theatre to look at the motivations of a group of young men, and a woman, training in Bobby Burgess's gym, a place where the trainer is god and the discipline is iron.

Here teenager Dina punches away her demons, and Ajay, Cameron, Ainsley and Neil, lads who – were it not for boxing might be punching each other's lights out on the street – know that with every drip of sweat and every punch they are getting closer to that moment when they might turn pro and have their three minutes of glory.

But the main event here is not the story, in which Ajay overreaches himself, Neil's future is snatched away and Cameron makes it into the ring, because to be honest it's a pretty familiar one. It's the way this story is told – through a mix of video, replays, a revolving stage and some astonishingly choreographed training sequences – that makes it so compelling.

Frantic Assembly turn something aggressive and male into something beautiful and painfully tender as they trace the exquisite thrill and exquisite pain that occurs when you push your body and reach out for the stars.

One of the most remarkable things about the evening is the sheer amount of sweat that drips from the actors' bodies. They are not acting this play; they are living it, their bodies sculpted, swaggering and shining like young gods.

Narrative and characters are a touch under-developed and there are times when the movement seems intrusive, but it's a brilliantly acted exploration of what makes boxers box and what happens when a shooting star shimmers, shines brightly and falls to earth.